Fluid cushioning mounting particularly for engines in motor vehicles

ABSTRACT

A dual-chamber support bed with hydraulic cushioning especially for engine mount in motor vehicles includes a working chamber and a compensating chamber filled with liquid have walls (3, 4) comprising annular rubber diaphragms with a predetermined buckling characteristic to adapt to the operating load the chambers are connected to one another through a nozzle channel. The nozzle channel is defined between profiled parts overlapping one another which are two rigid components of a housing that are adjustable to one another. The channel flow resistance is adjustable by means of a screw-driven regulating unit. The two components forming the nozzle channel there between are adjustable axially relative to one another in the direction of the vertical axis of the mount. One of these components is thread onto a spindle that can rotate freely in the housing. An operating member for rotating the spindle extends out of the housing, and can be screwed on it coaxially with the vertical axis.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates in general to resilient mounting devices and inparticular to a new and useful fluid cushioned mounting particularly forengines in motor vehicles.

Engine mounts with these features are disclosed by German PatentApplication Disclosure No. 34 10 781. It has a nozzle channel in a rigidpartition that separates the upper working chamber from the compensatingchamber located below it. The cushioning characteristics of the mountcan be adjusted. The nozzle channel is formed by disc recesses whichopen toward one another. The discs can rotate around a vertical axis ofthe mount and be brought into positions aligned for individualcushioning during the installation of the mount. Since the base of therecesses open toward one another has the design of an inclined plane,both the length and the cross section of the nozzle channel can bechanged by rotating the disks. However, this change can be made onlyduring the installation of the mount, or after partial disassembly ofthe mount. After installing the mount, no further adjustment ispossible. The behavior of the mount desired over the required frequencyrange is adjustable by the means mentioned, however, so that individualtolerances and inaccuracies can be adjusted by changing the length andthe cross section of the nozzle channel to an acceptable initial value.Nozzle channels between the two chambers of an engine mount are alsoknown with flow rates continuously adjustable electronically to controlthe cushioning characteristics of the engine mount. However, thenecessary technical expense exceeds by far the costs of a mount pursuantto German Patent Application Disclosure No. 34 10 781.

SUMMARY OF THE INVENTION

The invention provides an adjustment capability of dual-chamber supportbeds for the cushioning characteristics of the mount even after itsinstallation, and provides primarily a permanent adjustment capabilityof the cushioning behavior.

An outstanding advantage is the fact that the invention makes itpossible to control the cushioning characteristics even after theinstallation of the mount, so that a continuous adaptation of thecushioning characteristics to changing operating sates can be carriedout by constant adjustment. For this purpose, sensors in the vehicle canoptionally transmit the operating state to the control element for thecushioning characteristics in the mount by means of regulating units.Manual adaptation to a desired behavior is also possible at anysubsequent time in this way.

In a preferred form of embodiment, the compensating chamber extendsannularly round a central working chamber with the means for controllingthe cushioning characteristics being located in components of a housingfreely accessible from the outside. With such a design, the nozzlechannel is placed in an annular component that also serves as asupporting element for the annular rubber diaphragm of the wall of theworking chamber and is connected securely to a flat base section. Inthis way, the base section is readily accessible from the outside and isthus suitable for holding adjustable elements to control the cushioningcharacteristics of the support bed. In a dual-chamber support bed with anozzle channel concentric with the vertical axis of the mount in a planeacross it, the invention provides for one of the two components formingthe nozzle channel to engage with a raised profile in a correspondingdie profile of the other component and to be adjustable in this profileby means of the spindle. Since this spindle has the operating elementcoming out of the housing to the outside, a change of cross section ofthe nozzle channel can be carried out during the entire drivingoperation of the motor vehicle by simply turning the spindle. Thisadvantage makes it possible to control the cushioning characteristicsmanually or automatically.

According to another embodiment of the invention, it is provided thatthe die profile forming the nozzle channel, which is connected throughopenings to the working chamber and to the compensating chamber, issealed by an elastic diaphragm and the raised profile of the firstcomponent is adjustable relative to this diaphragm. The length of thenozzle channel is also directly variable by this diaphragm, since thecomponent coaxially adjustable by this seal can also be rotated relativeto the first component. Both an axial adjustment and a rotation of theadjustable component can be achieved by automatic stop elements or stopelements that can be operated from the outside.

Accordingly, it is an object of the invention to provide a fluid cushionmounting particularly for engines in motor vehicles which includes abase which is covered on its top by a resilient member which has basedupon resilient walls defining a compensating chamber there between whichcommunicates with a working chamber through a nozzle channel and whichincludes means for varying the flow through the nozzle channel.

A further object of the invention is to provide a resilient mountingwhich may be continuously adjusted so as to regulate the compensatingforce of a fluid support having an upper part which is connectable tothe motor to be supported and a base which is simple in design rugged inconstruction and economical to manufacture.

DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a vertical sectional view of an engine support mount,

FIG. 2 is a vertical sectional view of an engine support mountconstructed in accordance with another embodiment of the invention; and

FIG. 3 is a horizontal section taken along the line 3--3 of FIG. 2.

GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings in particular, the invention embodied thereincomprises a fluid cushion mounting generally designated 50 whichincludes a base portion 7 having upstanding walls with a top openingwhich is covered by a resilient member 52 which has spaced apart walls 3and 4 and a bottom recess which overlies the base member and defines aworking chamber 1 which communicates with a compensating chamber 2through a nozzle channel 3 which is defined between the base and theresilient member 52. In accordance with the invention means are providedfor varying the flow through the nozzle channel 8 in accordance withoperating conditions and in the embodiment of FIG. 1. this comprises asecond component member 9 which is movable in the base part 7 into anout of recess defining the nozzle channel 8 so as to vary the flowcross-section of the nozzle channel 8.

The embodiment of FIG. 1 shows a dual-chamber support or engine mount 50with hydraulic cushioning, especially for an engine mount in motorvehicles. The mount 50 includes a working chamber 1 and compensatingchamber 2 filled with liquid which have respective walls 3 and 4 made ofannular rubber diaphragms. The compensating chamber 2 extends annularlyaround a central working chamber 1, so that the rubber housing 52forming the walls 3 and 4 have a one-piece interconverted design. Rubberhousing 52 is connected securely to the upper, centrally located supportelement 5, that can be fastened to the engine or to another supportingpart. The free end of the rubber housing 52 forming the wall 3 of theworking chamber 1 is connected securely to a component or ring 6, thatcan be screwed to an annular base or housing 7 of the working chamber.

A nozzle chamber 8 in the example of embodiment according to FIG. 1 isformed from a matrix-shaped recess in the ring 6 and from a raisedprofile of a second ring or second component 9, whose raised profileengages in the matrix-shaped recess of the first ring 6. This secondcomponent 9 is cup-shaped in vertical section, so that the edge is thesame as or similar to the matrix-shaped design of the channel 8. Thesecond component 9 with a female thread is screwed to a centrallylocated spindle 10 that is mounted to rotate freely in the housing 7 andcan be rotated by means of an operating element 11 extending laterallyout of the housing. By rotating the spindle 10 around the vertical axis12 of the mount, an axial displacement of the second component 9 isproduced. The matrix profile in the first component 6 is sealed by meansof an elastic diaphragm or ring 13, so that edge of the second component9 works against this membrane 13 with its raised profile. This diaphragm13 is clamped in between the first component 6 and the base section ofthe housing 7 and advantageously has a one-piece construction along withan additional buckling spring 14 that represents another control elementfor changing the buckling characteristics of the rubber diaphragm walls3 and 4. The operating element 11 in the case of the example has theform of a lever extending laterally out of the housing 7 that is movablein a slot of the housing. To produce multiple spindle rotation by movingthe lever 11 in a limited slot, a ratchet connection 54 is providedbetween the lever 11 and the spindle 10. It is clear from the drawingthat both a rotation of the second component 9 and an axial displacementof this component can be produced by rotating the spindle 10, on the onehand to change the length of the nozzle channel 8 and on the other handto change its cross section.

In the example of embodiment according to FIGS. 2 and 3, a mount 50'includes the annular nozzle channel 8 which is located between the firstcomponent 6 for supporting the wall 3 of the rubber diaphragm 52' andthe edge of an inner disk 15 that is adjustable around the centralvertical axis 12 of the support bed, for example by rotation of thelever 11, that is connected to the spindle 10 as has already beendescribed in FIG. 1. There is a lip seal 16 between the component 6 andthe disk 15 that seals the gap between the two parts 6 and 15. Thenozzle channel 8 extending annularly for almost 360° is limited at oneend by a solid shaping or radial deflector 17 of the component 6 and atthe other end by a similar shaping 18 of the disk 15 which is adjustableby turning. The shaping 17 defines a nozzle channel 19 at the opening tothe compensating chamber 2, and the shaping 18 defines an opening 20 ofthe nozzle channel 8 at its connection into the working chamber 1. Thelength of the nozzle channel 8 can thus be adjusted by rotating the disk15 between almost 360° and 0°, with an appropriate cross section profileof the two parts 5 and 15 forming the nozzle channel 8 betweenthemselves also making it possible to adjust the channel cross sectionby turning the disk. The nozzle channel 8 must have a minimum lengthsuch that the resistances of the vibrating masses (buckling spring 14with an optional insert) are greater than the resistance that resultsfrom the size of the openings 19 and 20. A nozzle channel that is toosmall leads to undesirable action in the low-frequency range since theresistance of the openings 19 and 20 are the determining factors. Theknown drawbacks in the area of the hole can be avoided by suitablematching.

What is claimed is:
 1. A dual-chamber support bed with hydrauliccushioning for engine mount vehicles, having a working chamber and acompensating chamber filled with liquid, and walls defining saidchambers made of annular rubber diaphragms having a predeterminedbuckling characteristics adapted to an operating load, and beingconnected to a housing, first and second rigid components of saidhousing overlapping one another and forming a nozzle chamber, said firstand second rigid components of said housing being adjustable relative toone another, a rotatable spindle supported in said second component,said channel having a flow resistance which is adjustable by means of aregulating unit connected to said spindle, said first and secondcomponents being adjustable relative to one another in the direction ofthe vertical axis of the mount, and one of said components beingthreaded on said spindle which is rotatable freely in said housing, andsaid unit including an operating member extending out of said housing,said nozzle channel being positioned concentrically to the vertical axisin a plane perpendicular to it, said one component having a raisedprofile engaged in a corresponding die profile of said other componentand being adjustable in this profile, said nozzle channel having araised die profile which is connected by openings to the working chamberand to the compensating chamber and is sealed by means of an elasticdiaphragm, and the raised profile of the component is adjustablerelative to said diaphragm.
 2. A dual-chamber support bed with hydrauliccushioning for engine mountings in vehicles, having a working chamberand a compensating chamber filled with liquid, and walls defining saidchambers made of annular rubber diaphragms having a predeterminedbuckling characteristic adapted to an operating mode, and beingconnected to a housing having first and second rigid components havingportions overlapping one another and defining between them a nozzlechannel interconnecting said chambers, sealing means sealing theportions against one another, said first and second rigid components ofsaid housing being adjustable in axial positions relative to one anotherto vary the cross-sectional area and thereby the flow resistance of thechannel, an actuating spindle supported for free rotation in the housingby a regulating unit and in threaded engagement with one of said firstand second components for effecting said adjustment of its positionrelative to the other component in the direction of the axis by rotationof the spindle thereby to vary the cross-sectional area and the flowresistance of the channel, and said unit including an operating memberconnected to the spindle and extending out of said housing for effectingcontinuous rotation of the spindle thereby to adjust the flow resistanceof the channel during the operation of the vehicle.
 3. Dual-chambersupport bed pursuant to claim 2, said nozzle channel being positionedconcentrically of, and in a plane perpendicular to, the mounting axis,said one component having a raised profile engaging in a correspondingdie profile of said other component and being axially adjustable in thedie profile, the sealing means being an elastic diaphragm stretchingover and sealing off the die profile, the raised profile shaping thediaphragm into the die profile when the components are actuallyadjusted.
 4. Dual-chamber support bed pursuant to claim 3 wherein theoperating member is a lever movable in a slot in the housing andextending out of the housing laterally, ratchet means being provided toconnect the spindle to the lever.
 5. Dual-chamber support bed pursuantto claim 3 wherein said second component is adjustable coaxially withthe axis by means of said spindle (10) and has a cup-shaped design invertical cross section and has an edge pointing upward that forms theraised profile.